`const`-stablilize `NonNull::as_ref`
A bunch of pointer to reference methods have been made unstably const some time ago in #91823 under the feature gate `const_ptr_as_ref`.
Out of these, `NonNull::as_ref` can be implemented as a `const fn` in stable rust today, so i hereby propose to const stabilize this function only.
Tracking issue: #91822
``@rustbot`` label +T-libs-api -T-libs
Updated lines doc to include trailing carriage return note
Updated `str::lines` doc to include explicit info about (trailing) carriage returns.
Reference: #100311
fix(resolve): update the ambiguity glob binding as warning recursively
Fixes#47525Fixes#56593, but `issue-56593-2.rs` is not fixed to ensure backward compatibility.
Fixes#98467Fixes#105235Fixes#112713
This PR had added a field called `warn_ambiguous` in `NameBinding` which is only for back compatibly reason and used for lint.
More details: https://github.com/rust-lang/rust/pull/112743
r? `@petrochenkov`
Rollup of 7 pull requests
Successful merges:
- #113773 (Don't attempt to compute layout of type referencing error)
- #114107 (Prevent people from assigning me as a PR reviewer)
- #114124 (tests/ui/proc-macro/*: Migrate FIXMEs to check-pass)
- #114171 (Fix switch-stdout test for none unix/windows platforms)
- #114172 (Fix issue_15149 test for the SGX target)
- #114173 (btree/map.rs: remove "Basic usage" text)
- #114174 (doc: replace wrong punctuation mark)
r? `@ghost`
`@rustbot` modify labels: rollup
docs: fmt::Debug*: Fix comments for finish method.
In the code sample for the `finish` method on `DebugList`, `DebugMap`, and `DebugSet`, refer to finishing the list, map, or set, rather than struct as it did.
Optimize `AtomicBool` for target that don't support byte-sized atomics
`AtomicBool` is defined to have the same layout as `bool`, which means that we guarantee that it has a size of 1 byte. However on certain architectures such as RISC-V, LLVM will emulate byte atomics using a masked CAS loop on an aligned word.
We can take advantage of the fact that `bool` only ever has a value of 0 or 1 to replace `swap` operations with `and`/`or` operations that LLVM can lower to word-sized atomic `and`/`or` operations. This takes advantage of the fact that the incoming value to a `swap` or `compare_exchange` for `AtomicBool` is often a compile-time constant.
### Example
```rust
pub fn swap_true(atomic: &AtomicBool) -> bool {
atomic.swap(true, Ordering::Relaxed)
}
```
### Old
```asm
andi a1, a0, -4
slli a0, a0, 3
li a2, 255
sllw a2, a2, a0
li a3, 1
sllw a3, a3, a0
slli a3, a3, 32
srli a3, a3, 32
.LBB1_1:
lr.w a4, (a1)
mv a5, a3
xor a5, a5, a4
and a5, a5, a2
xor a5, a5, a4
sc.w a5, a5, (a1)
bnez a5, .LBB1_1
srlw a0, a4, a0
andi a0, a0, 255
snez a0, a0
ret
```
### New
```asm
andi a1, a0, -4
slli a0, a0, 3
li a2, 1
sllw a2, a2, a0
amoor.w a1, a2, (a1)
srlw a0, a1, a0
andi a0, a0, 255
snez a0, a0
ret
```
In the code sample for the `finish` method on `DebugList`,
`DebugMap`, and `DebugSet`, refer to finishing the list, map, or
set, rather than struct as it did.
`AtomicBool` is defined to have the same layout as `bool`, which means
that we guarantee that it has a size of 1 byte. However on certain
architectures such as RISC-V, LLVM will emulate byte atomics using a
masked CAS loop on an aligned word.
We can take advantage of the fact that `bool` only ever has a value of 0
or 1 to replace `swap` operations with `and`/`or` operations that LLVM
can lower to word-sized atomic `and`/`or` operations. This takes
advantage of the fact that the incoming value to a `swap` or
`compare_exchange` for `AtomicBool` is often a compile-time constant.
delete [allow(unused_unsafe)] from issue #74838
While looking into issue #111288 I noticed the following `#[allow(...)]` with a `FIXME` asking for it to be removed. Deleting the `#[allow(...)]` does not seem to break anything, it seems like the lint has been updated for unsafe blocks in macros?
Fix size_hint for EncodeUtf16
More realistic upper and lower bounds, and handle the case where the iterator is located within a surrogate pair.
Resolves#113897
Update the tracking issue for `const_cstr_from_ptr`
Tracking issue #101719 was for `const_cstr_methods`, #113219 is a new issue specific for `const_cstr_from_ptr`.
(I believe #101719 could also be closed)
```@rustbot``` label +T-libs-api +A-docs
remove the unstable `core::sync::atomic::ATOMIC_*_INIT` constants
Tracking issue: #99069
It would be weird to ever stabilise these as they are already deprecated.
Enable coinduction support for Safe Transmute
This patch adds the `#[rustc_coinductive]` annotation to `BikeshedIntrinsicFrom`, so that it's possible to compute transmutability for recursive types.
## Motivation
Safe Transmute currently already supports references (#110662). However, if a type is implemented recursively, it leads to an infinite loop when we try to check if transmutation is safe.
A couple simple examples that one might want to write, that are currently not possible to check transmutability for:
```rs
#[repr(C)] struct A(&'static B);
#[repr(C)] struct B(&'static A);
```
```rs
#[repr(C)]
enum IList<'a> { Nil, Cons(isize, &'a IList<'a>) }
#[repr(C)]
enum UList<'a> { Nil, Cons(usize, &'a UList<'a>) }
```
Previously, `@jswrenn` was considering writing a co-inductive solver from scratch, just for the `rustc_tranmsute` crate. Later on as I started working on Safe Transmute myself, I came across the `#[rustc_coinductive]` annotation, which is currently only being used for the `Sized` trait. Leveraging this trait actually solved the problem entirely, and it saves a lot of duplicate work that would have had to happen in `rustc_transmute`.
Uplift `clippy::fn_null_check` lint
This PR aims at uplifting the `clippy::fn_null_check` lint into rustc.
## `incorrect_fn_null_checks`
(warn-by-default)
The `incorrect_fn_null_checks` lint checks for expression that checks if a function pointer is null.
### Example
```rust
let fn_ptr: fn() = /* somehow obtained nullable function pointer */
if (fn_ptr as *const ()).is_null() { /* ... */ }
```
### Explanation
Function pointers are assumed to be non-null, checking for their nullity is incorrect.
-----
Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
`@rustbot` label: +I-lang-nominated
r? compiler
enable test_join test in Miri
Miri for quite a while now has a hack to support self-referential generators: non-`Unique` mutable references are exempt from aliasing conditions. So we can run this test now. (It passes.)
Also extend a comment in a Vec test, while I am at it.
